Image sensing system for a vehicle

Abstract

An image sensing system for a vehicle includes an imaging sensor and a logic and control circuit. The imaging sensor comprises a two-dimensional array of light sensing photosensor elements formed on a semiconductor substrate, and has a field of view exterior of the vehicle. The logic and control circuit comprises an image processor for processing image data derived from the imaging sensor. The image sensing system may generate an indication of the presence of an object within the field of view of the imaging sensor. Preferably, video images may be captured by said imaging sensor and may be displayed by a display device for viewing by the driver when operating the vehicle. The logic and control circuit may generate at least one control output, and the at least control output may control an enhancement of the video images.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of U.S. patent application Ser. No. 10 / 643,602, filed Aug. 19, 2003 (Attorney Docket DON01 P-1087), which is a continuation of application Ser. No. 09 / 776,625, filed on Feb. 5, 2001, now U.S. Pat. No. 6,611,202, which is a continuation of application Ser. No. 09 / 313,139, filed on May 17, 1999, now U.S. Pat. No. 6,222,447, which is a continuation of application Ser. No. 08 / 935,336, filed on Sep. 22, 1997, now U.S. Pat. No. 5,949,331, which is a continuation of application Ser. No. 08 / 445,527, filed on May 22, 1995, now U.S. Pat. No. 5,670,935, which is a continuation-in-part of patent application Ser. No. 08 / 023,918, filed Feb. 26, 1993, by Kenneth Schofield and Mark Larson, now U.S. Pat. No. 5,550,677.BACKGROUND OF THE INVENTION [0002] This invention relates generally to vision systems for vehicles and, more particularly, to rearview vision systems which provide the vehicle operator with scenic ...

AI Technical Summary

Benefits of technology

[0007] The present invention is directed towards enhancing the interpretation of visual information in a rearview vision system by presenting information in a manner which does not require significant concentration of the driver or present distractions to the driver. This is accomplished according to the invention in a rearview vision system having at least two image capture devices positioned on the vehicle and directed rearwardly with respect to the direction of travel of the vehicle. A display is provided for images captured by the image capture devices. The display combines the captured images into an image that would be achieved by a single rearward-looking camera having a view unobstructed by the vehicle. In order to obtain all of the necessary information of activity, not only behind but also along side of the vehicle, the virtual camera should be positioned forward of the driver. The image synthesized from the multiple image capture devices may have a dead space which corresponds with the area occupied by the vehicle. This dead space is useable by the driver's sense of perspective in judging the location of vehicles behind and along side of the equipped vehicle.

[0009] It has been discovered that such vertical compression substantially eliminates distortion resulting from the spatial separation between the cameras and can be readily accomplished. In an illustrated embodiment, the image compression is carried out by removing selective ones of the scan lines making up the image portion. A greater number of lines are removed further away from the vertical center of the image.

[0010] The compression of the central image portion produces a dead space in the displayed image which may be made to correspond with the area that would be occupied by the vehicle in the view from the single virtual camera. Preferably, perspective lines are included at lateral edges of the dead space which are aligned with the direction of travel of the vehicle and, therefore, appear in parallel with lane markings. This provides visual clues to the driver's sense of perspective in order to assist in judging distances of objects around the vehicle.

Problems solved by technology

Furthermore, rearview mirrors protrude a substantial distance from the side of the vehicle, which makes maneuvering in tight spaces more difficult.

The driver cannot perceive vehicles, objects, or other road users in such blind spots without turning his or her body, which interferes with forward-looking visual activities.

Camera-based rearview vision systems for vehicles have not obtained commercial acceptance.

One difficulty with proposed systems has been that they present a large amount of visual information in a manner which is difficult to comprehend.

This difficulty arises from many factors.

This may confuse the driver as to whether more than one object is present.

This results in different vertical positions on the display causing the elongated image to appear disjointed.

This makes the ability to judge distances in a camera system a problem.

Therefore, known camera systems fail to provide to the driver important information where that information is most needed—at small separation distances from surrounding objects.

Another difficulty with camera systems is that, in order to provide a sufficient amount of information, the camera system typically presents the driver with a greatly increased field of view.

However, an increased field of view is often obtained by utilizing a wide-angle lens which introduces distortion of the scene and further impairs the ability of the driver to judge distances of objects displayed.

The problem with such distortion of the scene is that the driver must concentrate more on the display and take a longer time to interpret and extract the necessary information.

This further distracts the driver from the primary visual task of maintaining awareness of vehicles and other objects in the vicinity of the driven vehicle.

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